As you reach weeks 28 to 32 of your pregnancy, you are now in the third trimester. This stage is marked by fast growth for your baby, new reactions to the world outside, and important final touches to their body systems. Your baby is not just growing passively anymore-they are starting to respond to light and sound from outside the womb and showing clearer patterns of being awake and asleep. Every movement you feel, no matter how small, is a sign of the amazing development happening inside you.
The third trimester lasts from week 28 until birth, which is usually around week 40. During this time, your baby is getting ready to live outside the womb. They’re gaining fat, maturing their organs, and their senses are sharpening. You may start to feel more tired or uncomfortable now, but these feelings are simply part of your baby’s big growth spurt as they get ready for life after birth. This time is about gaining strength and practicing important skills for their arrival.
Baby’s Development Between Weeks 28 and 32
Between weeks 28 and 32, your baby is hitting many milestones. They are growing bigger and stronger, and each week brings new changes as they get ready to be born. During this time, you’ll see a lot of important growth and new abilities developing.
The Size of Your Baby at Week 28
By week 28, the third trimester begins, and your baby is now about the size of a head of lettuce-around 13 inches from head to bottom, and about two pounds. You’ll notice their fingernails now reach the tips of their fingers, and small eyelashes are visible. At this point, your baby can open and close their eyes and respond to light for the first time.
As your baby grows, their skin starts to look less see-through and becomes smoother as fat builds up underneath. Adding fat helps your baby control their body temperature when they’re born. The hair on their head is also getting longer, making their features more defined. It’s impressive to see all the changes that have happened, and there’s still more growth ahead before birth.
Fast Growth and Gaining Weight
During the third trimester-especially weeks 28 to 32-your baby grows very quickly. By week 29, your baby may gain about seven ounces each week as more fat builds up, which will help keep them warm after birth. The soft hair called lanugo that covered your baby’s body starts to go away during these weeks, especially on the face. By week 32, babies are about 18 inches long and weigh close to five pounds.
Now that your baby is much bigger, there’s less space in your belly for them to move around. Most of the organs and body systems are finished developing by week 31. From this point on, your baby focuses on building up strength and putting on even more weight. The lungs are developing too, which is important if your baby is born early.
| Week | Average Length | Average Weight | Key Developments |
|---|---|---|---|
| 28 | 13 inches | 2 lbs | Opens eyes; responds to light; has eyelashes and fingernails |
| 29 | ~14 inches | 2.5 lbs | Gains about 7 oz per week; fat stores increase |
| 30 | ~15 inches | 3 lbs | Eyes open wide; hair grows longer |
| 32 | 18 inches | 5 lbs | Lanugo fades; less wrinkled skin |
Changes in How Your Baby Moves
As your baby gets bigger, the way they move will change. Early in the third trimester, you may still feel lots of kicks and even full turns. But as space becomes tighter, movements change to more gentle wriggling, stretching, and twisting. By week 32, there’s not much room for huge movements, so you might start to feel little hands, feet, or elbows pushing on your belly instead of big flips.
Even though space is limited, your baby is still very active! Many babies pick a favorite position around now, such as facing head-down. You’ll also start to notice sleep and wake cycles-times when your baby is active and when they’re quiet. Sometimes this means your baby moves around most at night or when you’re resting.
Sensory Growth: Reacting to Light and Sound
Your baby’s senses develop a lot during weeks 28 to 32. They can start to “meet” the world outside your belly through sight and sound. You might feel closer to your baby as they respond to your voice or things happening around you.
By week 28, your baby’s hearing is strong. They can notice different sounds, such as your voice or music, and may even remember familiar ones after they’re born. The eyes also improve a lot. Babies can open and close their eyes at this time and react to light. By week 30 to 33, they can even change the size of their pupils if there’s more or less light. These are big steps preparing your baby for life outside.
Your Baby’s Senses: Light, Sound, and Sleep
During weeks 28 to 32, your baby is not just growing, but also learning to notice the world around them. Their new sense abilities can lead to sweet moments as you see how they react to you and your surroundings.
How Does Your Baby React to Light?
Babies can react to light while still inside your belly. From week 28, their eyelids are partly open, and they can notice changes in brightness. By around week 30 to 33, their pupils can adjust if a strong light is nearby-like sunlight on your belly. If you shine a flashlight on your stomach, your baby might move or wiggle in response. This is their way of practicing seeing light before birth and helps their eyes get ready for the outside world.
Baby’s Hearing: Listening to Voices and Noises
By the third trimester, your baby can hear well. They can pick out different types of noises, from your heartbeat to your voice, and even outside sounds like music. Your baby also starts to recognize voices of people who talk or sing to your belly regularly. After they’re born, they may be calmed by familiar voices, showing how important these early sounds are. You can help your baby’s hearing by talking, reading, or softly playing music for them, building a strong bond before you even meet them face to face.
Sleep Cycles and Dreaming
Your baby is not awake all the time in the womb. By the third trimester, regular sleep and awake times begin, much like a newborn’s routine. Some parts of the day, your baby will be very active, while at other times, you may notice they are quiet and calm. Babies even show signs of REM sleep, which in adults is when we dream. This means your baby might already be experiencing dreams inside the womb! You may also notice thumb-sucking or gentle movements when they sleep. Learning these patterns now will help you understand your baby even more once they are born.
Questions You Might Have About Weeks 28-32
Many parents have questions at this stage, as things change quickly for both you and your baby. Knowing what’s normal and when to ask your doctor can help you feel more comfortable.
Is My Baby Growing Well?
It’s normal to wonder about your baby’s size and progress. At week 28, babies are usually about 13 inches long and weigh about two pounds. By week 32, they grow to around 18 inches and five pounds. Your doctor will keep track of your baby’s size and heartbeat at every checkup. Growth can vary, so there’s a wide range of what’s healthy. If anything is outside of what’s expected, your doctor will let you know and recommend more checks if needed. During this time, organs and the brain are maturing, and your baby’s body is learning to control temperature and practice breathing. Lungs keep developing, meaning better chances if birth happens early.
Should I Be Concerned If My Baby Moves Differently?
As your baby takes up more room, movements might feel less like strong kicks and more like gentle stretches or rolls. You should still notice regular movements every day, just in different patterns. Many doctors suggest doing “kick counts” from week 28 on: pick a time when your baby is usually active, and count how long it takes to feel 10 movements (kicks, rolls, flutters, or taps). Most people feel 10 moves within two hours. If you notice a big drop in movement, or it takes much longer to reach 10, call your doctor right away. Sometimes, changes are normal, but sometimes less movement can signal a problem. Always reach out to your healthcare provider if you are unsure.
How Can I Help My Baby’s Growth?
- Eat a healthy diet with plenty of iron, as babies take in most of their iron during the third trimester. Foods with iron include chicken, beans, spinach, tofu, and beef. Eating foods with Vitamin C can help your body use iron better.
- Interact with your baby by talking, singing, or reading aloud to your belly. Babies can hear and enjoy the sound of your voice.
- Try shining a gentle light on your belly and see if your baby reacts-this fun activity can build early bonds.
- Take care of yourself by getting enough rest, drinking plenty of water, and staying as active as your doctor recommends.
- Go to all your doctor’s appointments so your baby’s growth can be checked closely.
- Consider childbirth classes to get ready for labor, feeding, and baby care after birth.
Taking care of yourself is the best way to help your baby now. These weeks are about both physical growth and building a close connection before you meet your baby in person.